


On A Knife Edge

by thatnerdemryn



Category: Shadowhunters (TV)
Genre: Alternate Universe - Assassins & Hitmen, Assassin Magnus Bane, Begging, Blow Jobs, Dubious Morality, Knifeplay, M/M, Marking, Mildly Dubious Consent, Pissed Off Alec Lightwood, Restraints, Rope Bondage
Language: English
Status: Completed
Published: 2020-05-10
Updated: 2020-05-10
Packaged: 2021-03-02 20:13:20
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,073
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24112588
Author URL: https://archiveofourown.org/users/thatnerdemryn/pseuds/thatnerdemryn
Summary: “Alexand--”“Don’t.” Alec’s words were harsh, spitting with distaste. Magnus sighed and let his chin drop to his chest.“Do what you have to do, Alec.” Magnus closed his eyes. He knew it was stupid; that he should try to escape, fight for his life, or flea from his seemingly inevitable death. He couldn’t quite bring himself to make this harder on Alec, though.
Relationships: Magnus Bane/Alec Lightwood
Comments: 50
Kudos: 188





	On A Knife Edge

**Author's Note:**

> Well, I have no idea where this came from. But I had the idea and a wonderful prompt from [Morgan](https://skylar102.tumblr.com/), so I ran with it. Enjoy!

Magnus pulled at the ropes around his wrist, cursing to himself when he felt no give. He had to admit that Izzy was handier with them than he had expected. The intricate tie holding his hands behind his back was chafing his skin, uncomfortably tight and practically immovable. He found himself annoyingly impressed as he tried to pull his wrists apart again. The door flew open and Magnus listened carefully, the blindfold over his eyes making it impossible for him to discern who had entered. 

He didn’t hear the familiar click of heels, but Izzy could have removed them. He wouldn’t put it past her to aim for surprise with whatever she had planned. He tried to speak, but the fabric in his mouth muffled the noise. He tried to spit it out, his mouth drying with every word he muttered, the nervous sweat threatening to drip into his eyes. The fabric disappeared and Magnus stretched his jaw and licked his lips before a smirk formed on his face.

“I’m impressed. I haven’t been tied up in far too long. Though, I wish it was under different circumstances,” Magnus quipped. His senses were heightened enough for him to smell the immediately recognizable scent of sandalwood and gunpowder. “Alexander. Still cleaning up your sister’s dirty work I see,” Magnus teased, relaxing only slightly in his binds. 

“Magnus,” Alec said, elongating the final letter and causing a chill to shoot down his spine. “I see you’ve lowered your standards. Going after the good guys now?” Alec responded with venom in his tone. Magnus sighed and tilted his head, trying to see underneath the covering over his eyes. 

“Money’s money, kid. You know that as well as I do.” He felt the blade at his throat and inhaled sharply, pushing back in his chair as much as he could, but unable to fully back away from the cold metal of the knife. When he swallowed, he felt the sharp edge against his adam's apple and shivered. 

“But Izzy?” Alec asked. Magnus couldn’t ignore the shake in Alec’s voice as he said his sister’s name. He knew he couldn’t begin to explain to Alec why he took the job; Alec wouldn’t believe him even if he tried. 

“Are you going to kill me, Alexander?” Magnus asked. He wasn’t afraid of the answer. His job was always going to be his demise and he figured he’d rather go by the hands of someone as beautiful as Alec than anyone else. 

A bright light filled his vision as the blindfold disappeared, jostling his head. For a second, he thought the knife had sliced into his throat, but the feeling was gone and Magnus could breathe again. His eyes adjusted to the room, the only light to be seen trickling through the few windows lining the ceiling. His first thought was that he couldn’t escape. The Lightwood’s wouldn’t have brought him to a place he could escape. There was one door, behind Alec that was locked from the inside as far as Magnus could tell. It meant Magnus was dying inside the room or he was killing Alec. Both scenarios had him shuddering. 

“I need answers, Magnus,” Alec said, holding his knife at his side. Magnus could see his knuckles turning white around the solid grip. 

Magnus sighed. “I know how this works,” Magnus replied, his eyes meeting Alec’s for the first time in what felt like years. “And you know I can’t give them to you.” Magnus twisted his wrists in the binds, feeling the skin redden with each turn, raw from the untreated rope. He moved his ankles in the small struggle and realized they were chained, weighed down with the heavy metal. He glanced down at the chair he was sat in and grumbled to himself. 

“We wouldn’t dare use wood with an escape artist like you. You must have known we knew you better than that-- I knew you better than that,” Alec said, taking one step closer. “Are you going to make this hard for me?” There was regret in his tone like he was wishing Magnus wouldn’t make him do what they both knew needed to be done. 

“Alexand--” 

“Don’t.” Alec’s words were harsh, spitting with distaste. Magnus sighed and let his chin drop to his chest. 

“Do what you have to do, Alec.” Magnus closed his eyes. He knew it was stupid; that he should try to escape, fight for his life, or flea from his seemingly inevitable death. He couldn’t quite bring himself to make this harder on Alec, though. 

He heard the familiar shuffle of Alec’s feet across the cement floor and took a deep breath. He had always hoped his death would be quick. It was something that everyone in his chosen career path wanted. Usually, they ended up tortured for hours, days even, before they died slowly and horrifically. Magnus hoped Alec would make it quick and as painless as it could be. The knife pressing softly against his chin was the last thing he expected. 

“Look at me,” Alec commanded, his voice husky and practically a whisper. Magnus complied, because he didn’t have anything left to lose, but held his breath as his eyes connected with Alec’s. He saw the pity in them, the fear, the… betrayal. God, he wished he could tell Alec everything. “Why can’t you make this easy?” Alec asked, his voice breaking again. 

He didn’t expect the kiss; the fiery press of chapped lips and the saltiness of sweat and tears. But he took it gladly, wanting nothing more than to reach up and hold Alec’s face in his hands. He struggled in the binds, inhaling sharply as they cut further into his wrists. Alec’s tongue pressed into his mouth, exploring every inch of it like he had discovered a new world. Magnus was so focused on the heat emanating from Alec, he barely noticed the cold blade slicing down the front of his shirt. 

“Answers,” Alec asked against his lips, their foreheads pressed together. He could feel Alec’s breath against his face as he panted, from the kiss or from fear, Magnus didn’t know. Magnus kept his eyes closed, knowing that one look from Alec could have him changing his mind. He had to remind himself over and over that the less Alec knew, the longer he would stay alive. 

“I liked this shirt,” Magnus said dryly. In another scenario, Magnus knew he would see Alec’s signature eye roll and the fond look that often followed. Instead, he felt Alec’s damp lips trailing down the side of his neck, stopping at his collarbone to nip gently. The sharp tip of the knife circled around his exposed nipple, pressing into it in time with Alec’s teeth. Magnus threw his head back and stared up at the ceiling, hoping the cracked tiles and water stains would calm him down. 

“I know your weaknesses, Magnus. Every. Single. One.” Alec punctuated his words with light kisses down the center of Magnus’ chest, contrasting with the scratch of the blade following their trail. Magnus gulped and shook his head, trying and failing to hold back the chill that raced down his spine at the movements. 

“And you’re going to use them against me?” Magnus shot back, squeezing his eyes shut after he watched Alec kneel before him. He couldn’t stand the sight of Alec on his knees under regular circumstances and he thought it would break him. He rested the blade on the button of Magnus’ jeans and Magnus bit his lip to contain the moan that threatened to escape. 

“Don’t make me,” Alec pleaded. Magnus knew that if he looked down at Alec, he would see Alec’s widened eyes, the imploring gaze that made it impossible for Magnus to deny his whatever he wanted. Magnus also knew he couldn’t give him that, so he kept his eyes away, turning his head and squeezing them closed tighter. 

“I can’t,” Magnus said desperately. Alec had to understand why Magnus needed him to stop. He heard the knife click as it ran down each tooth of his zipper. It sounded like an explosion in the otherwise silent room. When the sound stopped, Magnus felt the smallest amount of relief until he felt the blade at his neck. It twisted, scraping underneath his ear and down his neck, the eerily similar design of the Lightwood sigil tattooed on Alec’s neck. 

Magnus turned back to Alec, the feeling of Alec’s mark on his skin overwhelming him. He didn’t even deserve the idea that Magnus could ever be part of the Lightwood’s. Alec threaded his hand through Magnus’ hair and tugged roughly, his neck exposed again as Alec’s teeth and tongue bit and sucked a darkened mark onto the sensitive skin. Magnus squirmed in his seat, pulling at his wrists and ankles with each twist of his body. 

“I can’t, Alec, please. Just kill me!” Magnus yelled, hoping his anguish was clear in the words. The ropes on his wrists weren’t giving in even as he twisted and tugged. He was hardening in his jeans with each passing second, his cock pressing uncomfortably to the material. Alec seemed to notice as a dark chuckle left his lips. 

“You can. You can tell me everything, Magnus. And we walk out of here, together.” The words sounded like the sweetest of promises and like Alec had truly believed them. Magnus knew better. He shook his head and bit down on his lip to hold in a cry. He could tell Alec was getting angry as the blade pressed harder against his skin. That was what Magnus wanted; for Alec to lose control and use the blade the way he was meant to. 

He heard the blade cutting through fabric again and his eyes snapped to his jeans. Both of his thighs were visible now, a line from the v of his groin to his kneecaps. Alec placed the knife between his teeth to rip at the fabric, exposing Magnus’ legs with each tear. Magnus gasped and tried to move his legs like it would change anything. Alec knew what he was doing, that much was clear to him. He knew exactly where to touch Magnus. He proved it as he dropped the blade from his mouth into his hand and trailed it along the top of his thigh, his eyes boring into Magnus’ with each centimeter. 

“I used to leave marks here. Ones that only you and I could see. Do you remember that?” Alec asked, nodding up at Magnus with a dark grin on his face. “They would be there for days, gone by the next time I got to see you.” The knife trailed to the inside of his thigh where a small yellowing bruise still stood out. Alec sighed and leaned down to kiss it, moving in between Magnus’ legs for a better angle. 

“Yes,” Magnus responded. Of course he remembered. How could he ever forget the minutes that Alec would spend between his legs, marking Magnus up to remind him who he belonged to. Magnus would remember the sight even in death, he thought. Alec bit down on the bruise and Magnus yelped, trying again for an unsuccessful tug at his wrists. He wanted to touch Alec; to run his fingers through his disheveled hair and push his face into his hardness where it belonged. He felt weak and needy and he figured Alec knew exactly what he was doing. 

Magnus jumped as he heard the blade drop to the ground, a clanging that seemed to trigger his fight reflex and he squirmed in the chair. He couldn’t tell if he was trying to get away from Alec or move closer, but he couldn’t do either. The feeling shot through his heart and straight into his groin. Alec unbuttoned his jeans and pulled them down roughly, the tattered fabric barely recognizable around his knees. His cock sprang out, thudding against his stomach wetly like it was begging for Alec’s attention. 

“Alexander, please,” Magnus begged. He didn’t want to show his weakness to Alec, but he already knew it was there. Alec already knew that it was only a matter of time before Magnus revealed everything to him. Magnus could tell by the dangerous smirk crossing Alec’s lips and the darkness that seemed to cloud his hazel eyes. 

“Answers, Magnus. All I need are answers and I’ll give you what we both want,” Alec bargained. His lips brushed over Magnus’ cock, his hot breath ghosting over it teasingly with every word. Magnus whined a desperate sound he had never heard himself make before. He couldn’t give Alec answers, but Magnus felt his resolve slipping with every single breeze that wafted across his skin. 

“Don’t make me, Alec, please. I can’t--” Magnus pleaded. Alec’s tongue darted out to lick his lips, brushing over the tip of Magnus’ cock on the process. Magnus pulled at his wrists one last time, a new strength seeming to overtake him as one hand slid out from the bindings. The other was still restrained, but Magnus didn’t care. He only needed one. 

His hand darted around to the front of him, threading through Alec’s hair before Alec had time to react. Magnus pushed Alec’s head down until his mouth slid over Magnus’ throbbing cock. Magnus moaned, louder than he should have, and it echoed through the empty warehouse. He was too aware of Alec’s hand creeping up his chest, the blunt handle of the blade Alec had grabbed up again pushing against his skin. Magnus was ready to admit defeat, ready for Alec to finally end whatever was happening between them, as he loosened his grip on Alec’s head. He expected the knife to slice, to cut into his skin for his final moment of darkness, but it pressed heavily against his throat. Magnus tightened his grip in Alec’s hair, urging him to finish the job, but the knife dropped, pressing flat against his chest instead as Magnus forced his cock deeper into Alec’s throat. 

Alec moaned against his sensitive skin, each vibration pulling Magnus closer and closer to the edge. He was so focused on the feeling Alec’s wet mouth, he barely noticed Alec untying his other hand. He should have reached for the knife at his chest, he knew that would have been the smarter thing to do. But Alec wanted Magnus to fuck his throat, to use him even though he had all the power, so Magnus complied, wrapping his newly freed hand around Alec’s throat. He could feel his cock sliding deeper and deeper with every thrust as Alec’s eager mouth worked. Magnus had never seen a more beautiful sight. 

“Alec, please, I’m--” Alec nodded against him, not bothering to pull back. Magnus remembered how much Alec loved to taste him and the knife laying heavy against his chest reminded him that he had no choice to give Alec what he wanted. Alec’s eyes darted up to Magnus’ and the fire in his gaze had Magnus throwing his head back as he came. He pressed his hips up as much as he could, using his hand to push Alec even further onto his cock. He could feel his own seed flowing down Alec’s throat as he swallowed and if he had any control left, it vanished at that. His moans reverberated through the room, bouncing off the walls with every pant and slick slide of Alec’s mouth as he bobbed on Magnus’ cock, drinking up every last drop. 

“Answers,” Alec demanded when Magnus’ hands fell to his sides. He pushed the knife against Magnus’ throat once again, but Magnus could feel his hesitation in the shakiness of the blade. He wrapped one hand around Alec’s wrist, the other pushing Alec’s hair back from his face. Magnus had never seen such fear in Alec’s eyes and it pained him in a way he couldn’t explain. 

“If I leave here alive, we’re all dead anyway, Alexander,” Magnus said. It was the only response he could give and he hoped, prayed to a god he was sure he didn’t believe in, that Alec would accept it. 

“You know I can’t kill you,” Alec admitted slowly, the knife dropping to the floor with a clang. Magnus looked down at Alec, sadness filling his eyes as he reached to pull up what was left of his tattered jeans. Alec leaned back, falling back onto the concrete floor with his elbows on his knees and his head hanging between them. Magnus reached down to slide the chains from underneath the chair legs before kneeling next to Alec and pressing a gentle kiss against his head. 

“I know that. And you know that I can’t kill you either. We’re going to figure this out, Alec,” Magnus promised as Alec glanced up at him. Alec grabbed Magnus’ hand and slid a key into it that Magnus assumed was for the front door. 

“Go. Whoever is after you will be here soon. I’ve got the clan waiting for my signal,” Alec said as Magnus hesitated. Leave it to Alec to be well prepared for a fight in any scenario. “They are on strict orders to let you escape, okay?” The words had Magnus’ heart leaping to his throat. He had thought the plan was death, for either or both of them. To know that Alec was going to let him leave alive the entire time was almost enough to have him stay and risk everything. Magnus leaned forward and connected their lips. He could still taste himself in Alec’s mouth and he sighed into the kiss, letting his tongue linger just a few moments too long as Alec pushed him back. 

“Go!” Alec demanded again. Magnus nodded and grabbed the familiar knife off of the ground before jogging toward the door. With one last look back at Alec, he left the warehouse, his heart beating rapidly in his chest. He caught a glimpse of Izzy out of the corner of his eye but pushed forward. He would find a way around this job. He had never needed to before; had never once backed out on a paycheck but the look in Alec’s eyes and the feel of Alec’s lips on his changed everything.  _ Damn Lightwood’s _ , he thought bitterly as he ran a hand across his neck where Alec had scratched in his family sigil.  _ Damn Lightwood’s and their stupid morals and beautiful faces.  _

**Author's Note:**

> If you enjoyed, please feel free to follow me on [Tumblr](https://archeryandeyeliner.tumblr.com/) and [Twitter](https://twitter.com/thatnerdemilyj/).
> 
> If your looking to scream about Malec and don't know where to go, come join a super fun [Discord](https://discord.gg/8Q8yBVg)!
> 
> Kudos make me smile and comments make me weep, so please leave them!


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